“On 12 November 2002, Osama Binladen issued a public statement which specifically targeted Canada for the first time for its collaboration with the United States in attempting to dismantle Al Qaida,” a 2002 Canadian intelligence report (pdf) noted.
With that statement in mind, the Canadian Security Intelligence Service (CSIS) conducted classified studies on the terrorist threat to Canadian transportation systems. Two of those classified studies have now been declassified and released in redacted form.
The declassified studies were obtained under Canada’s Access to Information Act by former Canadian intelligence officer and author Stéphane Lefebvre, who provided copies to Secrecy News.
At least some of the many redactions seem silly, for example: “Surface transportation presents a [adjective deleted] degree of vulnerability to terrorist attacks,” one study begins. The missing word is probably not “low” or “negligible.”
See “International and National Terrorist Threats to Surface Transportation,” CSIS Study #2002-3/26 (redacted) (3 MB PDF).
and “The International Terrorist Threat to Maritime Transportation,” CSIS Study #2003-4/02 (redacted) (2.7 MB PDF).